Defluoridation Potential of Rice Husk, Groundnut Shell as a Conventional Alternative for Fluoride Removal – A Review

Fluoride occurs naturally in our environment but we consume it in small amounts. Exposure can occur through dietary intake, respiration and fluoride supplements. The most important factor for fluoride presence in alimentation is fluoridated water. Fluoride content in groundwater has become a national issue affecting the entire India. When the recommended limit of fluoride by WHO is 1.5 mg/L, in some particular parts of India fluoride levels are as high as 35 mg/l. Increased fluoride intake causes dental fluorosis, skeletal fluorosis and neurological problems. Major problems associated with fluoride remediation are lack of cheap adsorbent to remove fluoride content in water for poor communities of India. Hence, development of community-based defluoridation unit is needed with a technique which is cost-effective, technologically simple in operation while being able to keep the fluoride level in permissible limits. On the basis of extensive investigations, different researchers have developed simple and economical domestic defluoridation processes. The present review gives a brief account of prevalence, sources of fluoride toxicity and cost effective defluoridation method carried out on effects of fluoride in the last few decades. Thus cost effective absorbent which has high efficacy in fluoride removal from water can be provided to poor communities thereby preventing fluorosis.